1. Field of the Invention
The present invention relates in general to safety glasses which provide protection for the eyes from missiles originating from a frontal direction. More particularly, the present invention relates to eyewear with sideshield protection for reducing instances of eye injury from missiles originating from a lateral direction to the wearer. Still more particularly, the present invention relates to sideshield protection for reducing discomfort to the wearer from objects striking the eyewear.
2. Description of Related Art
Safety glasses are well known in the prior art and are used to protect the eyes of an individual from airborne particles, high-velocity projectiles, wind, and the like. As used herein, and by those skilled in the art, the terms “safety glasses” or “eyeshields” typically mean a protective barrier in front of the eye. A “sideshield,” on the other hand, typically means a protective barrier to the side, above or below the eye which normally supplements safety glasses.
One relatively popular form of eye protection which incorporates side protection is commonly referred to as a “cover goggle.” Generally, cover goggles are comprised of a soft plastic frame and a somewhat more resilient plastic mono lens. The cover goggles are usually held in place on the wearer's head by means of an elastic strap. Cover goggles can be worn as stand-alone eye protection or, advantageously, may be worn over standard prescription eyeglasses. An example of cover goggles is U.S. Pat. No. 2,422,534 to J. E. Du Bois titled “Eye Shield” which is incorporated herein by reference in its entirity.
As those skilled in the art of eyeglass and side shield manufacture are aware, the basic shapes of eyeglass frames are derived from a market which is fashion oriented and driven. Thus, cover goggles, while being an effective eye safety device, often go unused even when readily available due to the wearer's sense of fashion and vanity.
On the other hand, standard eyewear that incorporates safety sideshields are less bulky and intrusive for the user, and often more importantly to the user, present less of a fashion faux pas. Examples of sideshields for typical eyewear can be found in the following U.S. patents, each incorporated herein in their entirety: U.S. Pat. No. 5,748,278 issued May 5, 1998 to Bennie F. Simmons, Sr. and titled “Eyeglass Shield for Removable Attachment to Eyeglass Lens Frames”; U.S. Pat. No. 6,393,609 issued May 28, 2002 to Bennie F. Simmons, Sr. and titled “Protective Sideshield Removably Attachable to an Eyeglass Frame”; U.S. Pat. No. 5,798,815 issued Aug. 25, 1998 and corresponding U.S. Reissue Pat. No. RE37,530 E issued Jan. 29, 2002, both to Hirschman et al. and titled “Method and Kit for Attaching Side Shields to Eyeglass Temples”; U.S. Pat. No. 5,548,351 issued Aug. 20, 1996 to Hirschman et al. and titled “Method and Kit for Attaching Side Shields to Eyeglass Temples”; U.S. Pat. No. 5,781,271 issued Jul. 14, 1998 to Richard R. Wheeler and titled “Portable Safety Sideshields for Eye Glasses”; U.S. Pat. No. 5,608,469 issued on Mar. 4, 1997 to Maurice J. G. Bollé titled “Sunglasses with Removable Side Shields”; U.S. Pat. No. 5,402,189 issued Mar. 28, 1995 to Vicki L. Gill titled “Side Shield for Eyeglasses and Method of Making the Same”; U.S. Pat. No. 4,726,075 issued Feb. 23, 1988 to Matthew T. Hinrichs and titled “Disposable Side Shield for Eyeglasses”; U.S. Pat. No. 3,165,754 issued Jan. 19, 1965 to Rodgers et al. and titled “Side Shield Mounting for Spectacles”; U.S. Pat. No. 2,900,639 issued Aug. 25, 1959 to E. P. Lindstrom and titled “Spectacle Attachment”; U.S. Pat. No. 2,840,821 issued Jul. 1, 1958 to Gay, Jr. et al. and titled “Side Shield Attachment for Goggles and Spectacles”; and U.S. Pat. No. 6,062,688 issued May 16, 2000 to Joseph F. Vinas and titled “Detachable Eyeglass Foam Shield.”
As may be apparent from the sideshields described in the above-identified patents, sideshields may be of various types. For example, some are permanently attached to the eyeglass frames and provide reasonable protection for the top, side, and bottom of the eye. Permanent sideshields have the advantage of being custom designed for accommodating a particular type of eyewear and offer the user an acceptable measure of protection, but usually little in the way of style. However, sideshields need not be permanently affixed to eyewear but instead may be temporary and removable. Removable sideshields are capable of being stored when not in use while the user may continue to wear the eyewear in a location not necessitating the use of safety sideshields. Removable sideshields have the advantage of being selectively affixed to the eyewear by the user. Sideshields that provide eye protection and which also fit a broad range of eyeglass frame shapes and sizes are known as universal sideshields. Universal sideshields have the further advantage of being fixably adaptable for fitting many types of eyewear and therefore may be made available for users at locations where sideshield protection is desirable but might not otherwise be available for a specific frame style and size. Moreover, universal sideshields enable users to couple the sideshields to fashion safety eyewear and thus maintain some semblance of style. Thus, eyewear used in conjunction with sideshields may be conventional safety glasses, with or without prescription lenses, or might instead be fashion safety eyewear, again, with or without prescription lenses.
As mentioned above, the basic shapes of safety eyeglass frames tend to follow dress or street wear fashion trends. As such, the frontal protective area is subject to wide fluctuations when on the one hand very large frames and lenses are in vogue and on the other when very narrow frames prevail with their inherently smaller lenses. As might be expected, narrow frames provide minimal frontal protection, yet are currently in high demand. Safety eyewear manufacturers quickly copy new trends in non-safety products for introduction into the industrial work place. This trend has resulted in the frames on safety glasses being somewhat narrowed thereby reducing the frontal protection afforded by current models of safety glasses.
The reduction in vertical frontal protection provided by the narrow frame and lenses adversely affects the lateral protection offered by side protectors, the sideshields. As may be understood from the prior art identified above, manufacturers have all but exhausted the shapes, configurations and methods of design and fabrication of sideshields. There are permanently affixed, detachable and universal versions of sideshields, as described immediately above. They may be designed to provide side protection only, side and top protection only, or the full cup style which provides roughly 180-degree protection, top-bottom-side. Those sideshields which provide side only, or side and top protection, generally incorporate flat, deflective or shock absorbing surfaces. Cup or full sideshields are generally arcuate in shape and to a large degree must follow the basic design and shape of the eyeglass frame front.
All prior art sideshields have one thing in common: the vertical dimension of the eyeglass frames dictates the amount of lateral/vertical protection provided by the side protector.
The amount of the frontal protective area, horizontal or vertical, is not specified in the current version of the AMERICAN NATIONAL STANDARD Z87.1, Practice For Occupational and Educational Eye And Face Protection or in the pending major revision which is due for publication in late 2002 or early 2003. This revision specifies the locations at which a sideshield protector shall be impacted by a 0.25 in. (¼ inch) steel ball having been fired by an air gun at a velocity of 150 feet per second. These mandated tests are conducted upon safety eyewear devices which have been placed upon an Alderson 50th percentile head form. The head form is adjusted such that the path of the projectile passes through the center of the anterior surface of either of the eyes of the head form. The head form is then rotated on an axis which passes vertically at the intersections of a sagital plane through the center of the front surface of the tested eye and a coronal (frontal) plane which is 10 mm (0.394 in.) posterior to the corneal plane which is tangent to the anterior surfaces of the eyes of the head form.
Testing of the sideshield is conducted while on the head form in the position previously described with the exception that the head form is rotated 90 degrees so as to properly position the sideshield for implementation of impact testing. Three impact locations are specified which utilize the center of the eye of the head form for reference:                1. impact the sideshield on a line which is on a plane with the center of the eye and 10 mm posterior to the center of the eye of the head form;        2. impact the sideshield 10 mm above and posterior to the center of the eye of the head form; and        3. impact the sideshield 10 mm below and posterior to the center of the eye of the head form.        
Those skilled in the art of dispensing and adjusting eyeglasses to the wearer's head are keenly aware that the wearer's eyes, and those of the Alderson head form, will rarely be positioned at the mechanical center of the lenses of the eyeglasses frames. To the contrary, the frames are generally positioned through design of the frame, such that the eyes are located well above the mechanical center of the frames and lenses.
A typical fashion-oriented safety frame measures 35.63 mm (1.40 in.) vertically and the maximum side impact exposure area of the side shield is 28 mm (1.10 in.). Assuming that the frames, as worn, will rest with the mechanical center of the lens only 5 mm (0.197 inch) below the center of the eye, simple mathematics tells us that the high velocity ¼ inch steel ball will miss the sideshield and potentially strike the head form in the region of the eye cavity and upon an actual human head and would inflect serious injury if not causing death.
Another reality not considered in the present eyewear testing regime is the amount of force exerted on the wearer as a result of a projectile impact. Clearly, if the projectile test is successful, the wearer should not experience any eye injury. However, the kinetic energy transferred from the projectile to the eyeglasses or sideshield does not dissipate in the eyewear itself, but instead is transferred in substantial part to the wearer along contact surfaces of the safety device. Consequently, the wearer may experience discomfort at contact surfaces.
Inasmuch as OSHA, in its regulation 29 CFR Part 1910.133, relies heavily on ANSI Z87.1 for procedures in determining compliance, the industry will find itself with hundreds of thousands of safety glasses which have non-compliant sideshields attached. The average cost of over $100 per pair to replace those devices now in use would be astronomical, and in the current economy could prove catastrophic to the economic well being of some entities. An even more tragic scenario would be if the employer or employee chose not to comply with the standard and the employee lost the sight of an eye, if not his life, in the event of an accident.